72 results about "Triangular element" patented technology

A set of supports are advantageously disposed on a top plate having a polishing surface useful for polishing workpieces, thereby applying substantially uniform pressure to the top plate. In a preferred embodiment, the supports are non-isosceles triangular elements distributed evenly at 45 degree increments around a ring-shaped top plate. This structure effectively compensates for radial stress variations arising from non-optimum positioning of support points with respect to the inner and outer diameters of the polishing surface.

The invention discloses a Delaunay triangular net-based road center line extraction method, and belongs to the technical field of geographic information data processing. The method comprises the steps of establishing buffer regions of road line data, and performing buffer region fusion; performing node encryption based on a graphic layer of the established buffer regions, and establishing a Delaunay triangular net by utilizing encrypted nodes; classifying triangular elements forming the triangular net according to geometric features, thereby obtaining feature points of all the triangular elements; connecting the feature points in sequence to obtain single-line data, and obtaining a final result through curve smoothing. Single-line road network data is obtained by single and double-line mixed road data, so that complex manual processing or a data re-collection process is avoided when data is obtained in the field of scientific research such as road network analysis and the like or application, a topological relation of the road data can be well kept, and result data meeting the requirements is obtained.

The invention discloses a direction-of-arrival estimation method based on sparse representation. The method mainly solves the problems that because a similar technology is large in calculation amount and low in angular resolution, the estimation speed of target reconnaissance and passive location is low and estimation errors in target reconnaissance and passive location are large. The method comprises the implementation steps: (1) acquiring output signals of an array and calculating a covariance matrix R of the signals, (2) constructing reconstructed sparse vectors through lower triangular elements of the covariance matrix R, (3) carrying out mesh generation on a spatial domain to construct a perfect base, (4) converting the direction-of-arrival estimation issue into the issue of solving a constrained optimization equation according to the sparse representation relation between the reconstructed sparse vectors and the perfect base, (5) solving the constrained optimization equation according to the convex optimization method to obtain the optimal estimation vectors, (6) drawing a magnitude spectrum according to the one-to-one correspondence of the optimal estimation vectors and spatial domain angles to obtain the direction-of-arrival value. By means of the method, the calculation speed of target reconnaissance and passive location is decreased, and the estimation errors in target reconnaissance and passive location are reduced. The method can be applied to target reconnaissance and passive location.

The invention provide a water and sand prediction method and system for a strong alluvial river based on data assimilation. The method particularly comprises the steps of using terrain elevation scatter data obtained by sampling to generate an irregular triangular terrain grid unit; obtaining water-sand information and initial field information of strong alluvial river inlet and outlet boundaries;taking triangular elements of terrain grids as control bodies, discretizing a two-dimensional water-sand model of the strong alluvial river, selecting a solution method for calculation, and obtainingcalculated values of the control bodes; acquiring riverway water and sand state information of the strong alluvial river in real time, establishing a real-time prediction model based on the data assimilation according to the water and sand state information, and obtaining assimilation state variables and parameter variables; finally, using a two-dimensional water and sand data assimilation modelto conduct water and sand prediction on the strong alluvial river. Through the above treatment, the real-time status of water and sand of the strong alluvial river can be effectively predicted, so that water and sand regulation can be regulated, and a basis is provided for flood control and disaster alleviation, water environmental protection and water resource management.

The invention provides a single satellite image-oriented self-acquired triangular element height calculation method. The method comprises the steps of calculating three angle parameters, namely a sun elevation angle, a sun azimuth angle and a satellite azimuth angle, according to direction information in a single satellite image and a relation between the sun azimuth angle and the sun elevation angle, performing equivalent expression on a satellite elevation angle through a building height and a building projection length, and finally calculating a triangular element height which does not contain the satellite elevation angle. The effect of realizing calculation on the height of a building in the single satellite image is good.

The invention which relates to the field of the geological modeling technology, provides a method for refined modeling and block recognition of a rock slope structure. The method comprises: (1), obtaining a triangular element grid and a structural plane geometric parameter of a slope free face by using a laser scanning technique; (2) transforming a triangular face unit into a body unit by a projection method; (3) realizing spatial distribution of a structural surface by using a three-dimensional network simulation technology; (4) with a plane where the structural plane is located, cutting an intersected body unit completely; and (5) carrying out blanking on a side surface of a cylindrical unit inside a rock mass, carrying out fusion with the cut body unit, and thus forming block body merging between structural surfaces, thereby realizing block body identification. Therefore, the field measurement data and the block identification are combined; the precision is high and the speed is fast; and the identified block form and number are not limited.

The invention relates to the technical field of array signal processing technology, especially relates to DOA (Direction Of Arrival) estimation of a wireless signal source, and particularly relates toa uniform circular array differential phase based single distributed source DOA estimation method. The method includes calculating a corresponding covariance matrix through output signals of different array elements of the uniform circular array; extracting exact upper triangular element phases of the covariance matrix and performing vectorization treatment, and obtaining a differential phase vector; obtaining single distributed source central azimuth angle estimation and central pitch angle estimation through least squares estimation. According to the invention, a two-dimensional DOA closed-form solution is obtained directly through the least squares method, spectrum peak search and eigenvalue decomposition calculation are avoided and complexity is reduced substantially.

Embodiments of the present invention provide a 2.5-dimensional viscoelastic wave numerical simulation method and apparatus in the frequency domain. The method comprises: establishing a 2.5-dimensionalviscoelastic wave equation in the frequency domain; determining an equivalent integral weak form of the 2.5-dimensional viscoelastic wave equation in the frequency domain; obtaining a finite elementcontrol equation by using the discrete of bilinear triangular elements; loading 3D point sources in the frequency domain; loading the stiffness to weaken the absorption boundary condition; determininga wavenumber sampling strategy, wherein the finite element control equation is large sparse linear equations, and a direct solution method is used to solve the equations to obtain a frequency-wavenumber domain wave field; and using a complex Simpson numerical integration method to approximate the spatial inverse Fourier transform to obtain a three-dimensional viscoelastic wave field in the frequency domain. The present invention provides an accurate forward modeling method for 2.5-dimensional viscoelastic wave multi-scale full waveform inversion, and the method can adapt to any undulating surface complex medium, has a good absorption effect of the absorption boundary condition, and has high calculation efficiency.

The invention discloses a traffic data feature extraction method, a malicious traffic identification method and a network system. The feature extraction method comprises the steps of S1, obtaining traffic data including m data streams, extracting n features from each data stream, and constructing a matrix X; S2, performing normalization processing on the matrix X to obtain a feature value matrix;S3, solving the similarity of every two elements in each column of data for the feature value matrix to construct a self-similarity matrix of corresponding features of the column of data; S4, solvinga feature value histogram of features corresponding to each column of data of the feature value matrix; taking an upper triangular element of the self-similarity matrix of each feature to obtain a feature difference histogram; combining the feature value histogram and the feature difference histogram of each feature into a feature vector; and S5, integrating the vectors of the n features into a feature vector of the traffic data. The feature vectors have variation tolerance capability for the traffic features and are used as input of the classification model, so that the classifier can accurately identify malicious traffic and variants thereof.

The invention belongs to the technical field of radar, and discloses a method for estimating the DOA (direction of arrival) of a meter wave radar based on a two-dimensional convolution neural network.The method comprises the steps of obtaining P plots as a training set; calculating the covariance matrix of each plot in the training set and obtaining the corresponding phase average matrix and phase standard deviation matrix, wherein phases corresponding to upper triangular elements form an upper triangular element phase matrix; using the phase matrix corresponding to the i plot and subjected to zero filling and rearrangement as the input of the convolution neural network, and the output matrix of the convolution neural network corresponding to the i plot is obtained; modifying thenetwork parameters of the convolution neural network according to an objective function; and obtaining an actually measured target plot, and inputting the phase matrix of the actually measured targetplot into the convolution neural network to reconstruct the covariance matrix of the actually measured target plot to estimate the DOA of the target plot. Thus the DOA estimation problem is transformed into a pure regression problem.

The invention discloses a near-field source positioning method based on factor analysis, and aims to solve the problems that a traditional subspace method is complex in calculation, cannot perform real-time processing and is poor in parameter estimation performance under a low signal-to-noise ratio. According to a neural network method, upper triangular elements of a covariance matrix of trainingsample signals are generally used as features of the signals to perform network training, and in a large array with a large number of array elements, the upper triangular elements of the covariance matrix of the signals are used as input signal features, so that the complexity of a neural network is improved, and the network training time is prolonged. Therefore, the invention provides the near-field source signal positioning method for dimension reduction by using the factor analysis method. According to the method, a few reconstructed feature variables are used for replacing original featurevariables to research and analyze things, so that the feature dimension of the network input signals is reduced, the input signal features after dimension reduction are used for training of the neural network, the training speed is increased, the real-time performance of the algorithm is high, and the engineering application value of the method is enhanced.

The present invention discloses a groundwater flow calculation method. The method comprises steps: S1. solving a numerical model of a groundwater flow by using a triangular continuous Galerkin finite element method, and forming an original triangular element mesh and obtaining water head field data of the groundwater; S2. carrying out refinement of the original triangular element mesh to construct a partial equilibrium domain; and and S3. calculating a relevant flow value of the partial equilibrium domain. The method disclosed by the invention proposes two flow calculation methods that can ensure conservation of mass in an equilibrium domain by using the continuous Galerkin finite element method to calculate a water head field of the groundwater, so as to improve the accuracy of a flow field of the groundwater based on the triangular continuous Galerkin finite element method and the relevant calculations thereof.

A method to improve the accuracy of the frame antenna profile. Firstly, the reflective mesh surface is separated from the folded rods and the faceplate nodes, and an adjustable support column of a certain height is added to the faceplate nodes, and then the reflective mesh surface is decomposed. Add adjustable cables on top, add straps between the adjustable support columns and adjustable cables, divide the triangular units on the upper surface of each frame into several small triangular units, and finally sew the reflective mesh on the straps . This method adopts the design idea of ​​separating the frame structure from the reflective mesh surface, re-decomposes the reflective mesh surface, and increases the number of basic triangular units while keeping the quality characteristics, mechanical properties, and expansion methods of the main structure of the frame unchanged. The side length of the triangle unit is shortened, thereby improving the theoretical surface accuracy of the reflective mesh surface.

The invention discloses a method for improving the local refinement quality of a finite element mesh. The method includes: an encryption partition step: a region to be refined is determined on an initial region which has been refined by a finite element two-dimensional element mesh, in the region to be refined, the region to be refined is refined by a finite element two-dimensional element mesh with a smaller mesh cell size and a higher density, and after refinement, a triangular element exists in the peripheral region of the region to be refined; a triangular element removal step: a triangular element is selected, one or more mesh elements adjacent to the triangular element are selected, the triangular element and the mesh element form a transition region together, and the transition region has a quadrilateral contour, in the transition region, the original triangular element and the mesh element are eliminated, and the transition region is refilled with a plurality of quadrilateral elements. For each triangle element in the peripheral region of the area to be encrypted, a triangle removal step is sequentially performed until all the triangle elements are removed.

The invention discloses a near-field source positioning method of an array PCA-BP algorithm with array errors. The method comprises the steps of Receiving K narrow-band, non-Gaussian and stable near-field sound source signals by using a uniform linear array, generating N groups of array receiving signal data in a training interval, extracting an upper triangular element of a covariance matrix of the array receiving signal data as a signal feature matrix, and performing PCA dimension reduction to obtain a dimension-reduced signal feature matrix; inputting the dimension-reduced signal feature matrix and the corresponding expected output into a BP neural network for training, and including the array error in the BP network through training, thereby obtaining a trained network estimation modelin the presence of the array error; and estimating near-field source parameters by using the trained network model. By using the array PCA-BP algorithm, errors are prevented from being corrected, thecalculation amount of the algorithm is reduced, the estimation performance of the algorithm under the low signal-to-noise ratio is improved, and good noise immunity is achieved.

A method for predict that condensing performance of a triangular element splice parabolic film condenser is characterized in that the method at least comprises the follow steps: step 1, establishing areflective film surface of the condenser; 2, calculate that normal vector of each triangular element by using the topological relation of the triangular element and the vertex coordinates; 3, simulate a solar cone model by considering incident solar ray, and generating incident points of rays on a small flat surface of a triangular element at random by use a Monte Carlo method; 4, calculate thatray equation reflected by the triangular element by use the Fresnel principle; 5, calculate that coordinate of the intersection point of the reflected light ray and the receive surface, wherein the coordinate value of the intersection point is the coordinate of the light ray reflected by the triangular element and the receiving surface; 6, collect that intersection point and the energy of the light reflected by the receive surface and calculating the distribution of the energy flow density. The invention can simulate the distribution of the received surface energy flow density under the conditions of different incident angles of the light rays.

The invention relates to an electric power system node impedance matrix Z solving method based on CU triangular decomposition and belongs to the field of electric power system analysis and computing. The method mainly includes the steps of forming a node admittance matrix Y; performing quick CU triangular decomposition on the matrix Y; solving a matrix Wk through CWk=Ek; solving non-diagonal elements of a diagonal element Zkk and the diagonal element above the diagonal element Zkk of a matrix Zk through UZk=Wk; solving non-diagonal elements on the left of the diagonal element Zkk in accordance with the symmetry; writing data of a matrix Z to a data file. According to the electric power system node impedance matrix Z solving method based on CU triangular decomposition, a CU triangular decomposition method higher in calculation efficiency than a LDU triangular decomposition method is used for solving elements of the matrix Z, the symmetrical relationship between elements of a matrix Y and elements of a matrix C and a matrix U is used for quickly forming a composite matrix of a factor matrix C and a factor matrix U, and the symmetry of the matrix Z and the calculation order of elements of the matrix Zk is used for omitting back substitution solving of lower triangular elements of the matrix Z for achieving direct solving, so that the speed of formation of the matrix Z is greatly improved. Compared with the traditional LDU triangular decomposition method, the electric power system node impedance matrix Z solving method based on CU triangular decomposition has the calculation speed increased by about 33% when the method is used for IEEE-30, IEEE-57 and IEEE-118 node system checking calculation.

The invention relates to a method for measuring deformation of a discontinuous body containing a structural plane. The method comprises the following steps of (1) taking photos of a given discontinuous body containing a structural plane and inputting the photographs into finite element software; separately generating triangular elements for different structural planes of the discontinuous body andoutputting corresponding node files and element files; (2) generating interior points; (3) solving the displacement of the interior point; (4) solving the vertex deformation function of triangular block; 5) converting that vertex displacement to physical displacement; (6) visualizing the displacement. The method of the invention can be specially used for the deformation measurement of the discontinuous body, and can better reflect the displacement situation of the discontinuous body, so that the method can be better applied to the deformation measurement of a rock sample containing a joint ora crack surface.